Olanzapine (Zyprexa): Uses, Warnings and Key Facts

What is olanzapine?

Olanzapine is a medicine used in the treatment of schizophrenia and bipolar disorder. It is also described in the source as an antipsychotic, antimaniac, and mood-stabilizing medicine.

The source lists the following product ingredients: olanzapine hydrochloride, olanzapine pamoate, and olanzapine tartrate.

How olanzapine works

Olanzapine acts on several receptors in the brain, including serotonin, dopamine, cholinergic muscarinic, alpha-1 adrenergic, and histamine receptors. This broad receptor activity is part of why it can affect mood, behavior, and psychotic symptoms.

Uses and therapeutic indications

According to the source, olanzapine is used for:

• Schizophrenia
• Relapse prevention in bipolar disorder
• Manic episodes, either alone or in combination treatment
• Rapid control of agitation and altered behavior in schizophrenia or manic episodes when oral treatment is not adequate

How it may be given

Olanzapine may be given as tablets, orally disintegrating tablets, or intramuscular injection, depending on the product and the clinical situation.

Oral forms

Tablets may be taken with or without meals. Orally disintegrating tablets may also be taken with or without food and are designed to disperse quickly in the mouth. The source notes they should be taken immediately after opening the blister.

Intramuscular form

The source describes intramuscular olanzapine as an option for rapid control of agitation and altered behavior when oral treatment is not adequate. It also notes that oral treatment should be started as soon as possible afterward.

Dosage information in the source

The following dosing details are included in the original content. They are presented here for reference only and should be verified in the official leaflet or by a healthcare professional.

Because dosing depends on the product, age, liver or kidney function, and the reason for use, the official prescribing information should always be checked.

Contraindications listed in the source

• Hypersensitivity to olanzapine
• Narrow-angle glaucoma

Warnings and precautions

The original content highlights several situations that require caution, including:

• Children, where experience is limited
• Older adults
• People with dyslipidemia
• Prostatic hypertrophy or paralytic ileus
• History of seizures
• Liver enzyme elevation or signs of hepatic dysfunction
• Use with medicines that may affect the liver or prolong the QTc interval
• Congenital long QT syndrome, heart failure, cardiac hypertrophy, low potassium, or low magnesium
• Low white blood cell or neutrophil counts
• Conditions associated with hypereosinophilia or myeloproliferative disease

The source also notes a risk of tardive dyskinesia with prolonged exposure, and says caution is recommended with other central nervous system medicines or alcohol.

Metabolic and blood sugar monitoring

The source warns about hyperglycemia and possible worsening or onset of diabetes, sometimes with ketoacidosis or coma. It also mentions monitoring weight and blood glucose at specific intervals in people with diabetes or at risk of diabetes.

Serious reactions mentioned in the source

• Neuroleptic malignant syndrome
• Hepatitis
• Sudden cardiac death
• DRESS syndrome

Important notes about intramuscular olanzapine

The source says intramuscular olanzapine should not be given to patients with acute myocardial infarction, unstable angina, severe hypotension, bradycardia, sick sinus syndrome, or after heart surgery.

It also states that combining intramuscular olanzapine with parenteral benzodiazepines is not recommended, and that patients should be monitored for hypotension, bradyarrhythmia, and hypoventilation.

Liver and kidney impairment

The original content advises considering a lower starting dose in liver failure and kidney failure. It also includes product-specific notes for certain injection regimens. These details should be confirmed in the official leaflet for the exact formulation being used.

Drug interactions

The source lists the following interaction points:

• Reduced concentration: tobacco, carbamazepine
• Increased concentration: fluvoxamine or other CYP1A2 inhibitors
• Reduced oral bioavailability: activated charcoal
• Possible antagonism: direct and indirect dopamine agonists

Pregnancy and breastfeeding

The source notes that newborns exposed to antipsychotics during the third trimester may be at risk of extrapyramidal symptoms and withdrawal syndromes, so newborn monitoring is mentioned.

For breastfeeding, the source states that olanzapine is excreted in breast milk and that breastfeeding should be discouraged for mothers treated with olanzapine.

Driving and operating machinery

Olanzapine can cause drowsiness, dizziness, visual changes, and slower reaction time. The source advises caution when driving or using dangerous machinery, especially until individual sensitivity is known.

Adverse reactions and side effects

Side effects listed in the source include:

• Weight gain and increased appetite
• Increased glucose, triglycerides, and cholesterol
• Drowsiness
• Dyskinesia, akathisia, and parkinsonism
• Orthostatic hypotension
• Leukopenia and neutropenia
• Transient anticholinergic effects
• Asymptomatic increases in ALT and AST
• Rash, joint pain, fatigue, edema, and fever
• Raised alkaline phosphatase, CPK, GGT, uric acid, and prolactin
• Injection-site malaise, bradycardia, hypotension, syncope, or tachycardia with intramuscular use

What to verify in the official leaflet

If you are comparing olanzapine products, it is useful to confirm the exact formulation, route of administration, and patient instructions in the official leaflet or medication guide. This is especially important for:

• Oral tablets versus orally disintegrating tablets
• Intramuscular products
• Use in older adults
• Use in liver or kidney impairment
• Possible interactions with other medicines, alcohol, or smoking

Safety reminder

FAQ

Sources and reference links

The original content cites FDA and USP-based ingredient information and recommends checking the FDA medication guide for the specific drug product.